<!DOCTYPE html>
<html>
<head>
    <title>Your Page Title</title>
    <style>
        body {
            font-family: Arial, sans-serif;
            margin: 0;
            padding: 0;
        }

        /* Header styles */
        header {
            background-color: #333;
            color: #fff;
            padding: 10px;
            text-align: center;
        }

        header a {
            color: #fff;
            text-decoration: none;
            margin-right: 20px;
        }

        /* Navigation styles */
        .tab {
            overflow: hidden;
            background-color: #f1f1f1;
        }

        .tab button {
            background-color: inherit;
            float: left;
            border: none;
            outline: none;
            cursor: pointer;
            padding: 14px 16px;
            transition: 0.3s;
        }

        .tab button:hover {
            background-color: #ddd;
        }

        .tab button.active {
            background-color: #ccc;
        }

        /* Tab content styles */
        .tabcontent {
            display: none;
            padding: 20px;
        }

        /* Form styles */
        form {
            display: inline-block;
        }

        input[type="text"] {
            padding: 8px;
            border-radius: 4px;
            border: 1px solid #ccc;
        }

        button[type="submit"] {
            padding: 8px 16px;
            background-color: #4CAF50;
            color: white;
            border: none;
            border-radius: 4px;
            cursor: pointer;
        }

        button[type="submit"]:hover {
            background-color: #45a049;
        }
    </style>
</head>
<body>

<header>
    <a >Instructor</a>
    <form action="/search" method="GET">
        <input type="text" name="query" placeholder="Search...">
        <button type="submit">Search</button>
    </form>
    <form action="/massage" methods=['POST']>
        <input type="submit" value="Massage">
    </form>
    <form action="/logout" method="post">
        <input type="submit" value="Logout">
    </form>
</header>

<div class="tab">
    <button class="tablinks" onclick="openTab(event, 'lecture')">Lecture</button>
    <button class="tablinks" onclick="openTab(event, 'student_list')">Student List</button>
    <button class="tablinks" onclick="openTab(event, 'assignments')">Assignments</button>
</div>

<div id="lecture" class="tabcontent">
    <h3>Lecture Content</h3>
    <p>This is where lecture content goes.</p>
</div>

<div id="student_list"  class="tabcontent">
    <h3>Student List</h3>

    <table id="student_table">

        <thead>
            <tr>
                <th>Student ID</th>
                <th>Student Name</th>

            </tr>
        </thead>

        <tbody>
            {% for student in students %}
            <tr>
                <td>{{ student[0] }}</td>
                <td>{{ student[1] }}</td>
            </tr>
            {% endfor %}
        </tbody>
    </table>
</div>

<div id="assignments" class="tabcontent">

     <form action="/add_assignment" method=['GET']>
        <input type="submit" value="Add Assignment">
    </form>
    <form action="/I_feedback" >
        <input type="submit" value="Grading and Feedback">
    </form>
</div>

<script>
    function openTab(evt, tabName) {
        var i, tabcontent, tablinks;
        tabcontent = document.getElementsByClassName("tabcontent");
        for (i = 0; i < tabcontent.length; i++) {
            tabcontent[i].style.display = "none";
        }
        tablinks = document.getElementsByClassName("tablinks");
        for (i = 0; i < tablinks.length; i++) {
            tablinks[i].className = tablinks[i].className.replace(" active", "");
        }
        document.getElementById(tabName).style.display = "block";
        evt.currentTarget.className += " active";
    }
</script>

</body>
</html>